49: Saturn’s Rings

The rings of icy dust around Saturn are so much younger than the planet. Where did they come from and why are they going away?

Saturn’s Rings Transcript:

Welcome to Brain Junk, I’m Amy Barton, and I’m Trace Kerr and it’s time for a Brain Storm.

TK: So Amy, Saturn’s got lots of rings around it, we’ve seen that.

AB: Yes!

TK: Well, scientists have wondered if Saturn was ‘born’ with it’s rings. Like if it all came together and those rings were there, and it turns out that’s not the case.

AB: Really.

TK: Yeah.The rings are relatively young and they’re disappearing.

AB: Really? So we are at the apex and they’re headed back down?

TK: Yes. The planet is somewhere around 4 billion years old and the rings are about 100 million years old. They formed pretty recently. Where did they come from in the first place?
AB: Yes, and I’m concerned…

TK: And the best guess right now is that icy moons collided and the debris stuck. It got pulled in by Saturn’s gravity and now it’s going around, and around, and around. And they’ve found that the rings are slowly getting pulled into the planet.

AB: Not out and away.

TK: No. So James Donahue of NASA’s Goddard Space Flight says that the ring rain that is being pulled into the planet drains an amount of water product that could fill an Olympic size swimming pool from Saturn’s rings in a half an hour. So it’s gravity that’s doing the pulling of the rings toward the planet as a rain of icy dust. And, ok, so how do we even know this?

AB: Yes!

TK: OK. So the following particles interact with Saturn’s upper atmosphere, the ionosphere, and as these particles are falling they become charged and these ions glow in infrared light. So the Keck Telescope, which we’ve got up there looking around the universe, they pointed that at Saturn, and they can see this glow.

AB: Neat!

TK: Yeah. Scientists estimate that the rings will be gone in about 300,000 million years.

AB: Oh, we are not going to see this in our lifetime. I was standing here thinking “OK, so it’s gaining more mass, and is that going to upset it from it’s rotation, and Doomsday!”

TK: No.It’s just the water is falling down to the planet.

AB: It’s cool?
TK: Yeah, But there is a theory, though, that if this is true, if Saturn was not born with it’s rings and it’s slowly taking them into the planet, that it might be that Jupiter, Uranus and Neptune, that have very thin ring systems, might have at one time had much more substantial ring systems, and we’re just seeing them at the end of their process.

AB: That makes sense. That’s interesting. So much to know about space.

TK: I know, right?

AB: I’m always amazed at how scientists can know something that happened 300,000 million years ago and they’ve got the data to back it up.

TK: And math!

AB: Math.

TK: They’ve got math. I don’t really like math, so yeah, I’m just going to stick with the Keck Telescope and the really cool stuff.

AB: That is really cool.

TK: And that is my Brain Storm.

AB: Want to hear more? We’re on Facebook and Instagram as BrainJunkPodcast and Twitter as @MyBrainJunk. Trace and I will catch you next time with more of everything you never knew you wanted to know, and I guarantee you won’t be bored.